A management system is proposed which is provided with a management server that communicates with image forming apparatuses via a network such as an Internet. Here, in a network environment where a firewall is provided in a local network in which image forming apparatuses are deployed, it is impossible to directly issue a setting modification instruction, a reboot instruction or the like to an image forming apparatus from the management server. Therefore, in this type of network environment, the image forming apparatus polls the management server to inquire about the existence of instructions.
Patent Document 1 discloses a device management system in which, if an inquiry about the existence of instructions is received in passing from a management target device, and if an instruction exists, the management server returns the instruction in the operative session upon receipt of the inquiry.